From 58b407556607add3801b49eda7ae100ac208d5e2 Mon Sep 17 00:00:00 2001
From: Alex Jiang <alex.jiang@outlook.com>
Date: Thu, 19 Apr 2018 21:20:23 +0800
Subject: [PATCH] hostname: bug fix for non-windows xgethostname and add test
 case

Cstr::from_bytes_with_nul needs input bytes null terminated. Current
version does not include the last null byte, hence
Cstr::from_bytes_with_nul will panic with error 'FromBytesWithNulError {
kind: NotNulTerminated }'
---
 src/hostname/hostname.rs |  7 +++----
 tests/test_hostname.rs   | 12 ++++++++++++
 tests/tests.rs           |  3 ++-
 3 files changed, 17 insertions(+), 5 deletions(-)
 create mode 100644 tests/test_hostname.rs

diff --git a/src/hostname/hostname.rs b/src/hostname/hostname.rs
index 23ad3b4e9..80b60a699 100644
--- a/src/hostname/hostname.rs
+++ b/src/hostname/hostname.rs
@@ -157,13 +157,12 @@ fn xgethostname() -> io::Result<String> {
     };
 
     if err == 0 {
-        let mut last_char = name.iter().position(|byte| *byte == 0).unwrap_or(namelen);
-        if last_char == name.len() {
+        let null_pos = name.iter().position(|byte| *byte == 0).unwrap_or(namelen);
+        if null_pos == namelen {
             name.push(0);
-            last_char += 1;
         }
 
-        Ok(CStr::from_bytes_with_nul(&name[..last_char])
+        Ok(CStr::from_bytes_with_nul(&name[..null_pos + 1])
             .unwrap()
             .to_string_lossy()
             .into_owned())
diff --git a/tests/test_hostname.rs b/tests/test_hostname.rs
new file mode 100644
index 000000000..8df10b166
--- /dev/null
+++ b/tests/test_hostname.rs
@@ -0,0 +1,12 @@
+use common::util::*;
+
+#[test]
+fn test_hostname() {
+    let ls_default_res = new_ucmd!().succeeds();
+    let ls_short_res = new_ucmd!().arg("-s").succeeds();
+    let ls_domain_res = new_ucmd!().arg("-d").succeeds();
+
+    assert!(ls_default_res.stdout.len() >= ls_short_res.stdout.len());
+    assert!(ls_default_res.stdout.len() >= ls_domain_res.stdout.len());
+}
+
diff --git a/tests/tests.rs b/tests/tests.rs
index b1362dd0a..08552a4d5 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -91,6 +91,7 @@ generic! {
     "tsort", test_tsort;
     "unexpand", test_unexpand;
     "uniq", test_uniq;
+    "wc", test_wc;
     // Be aware of the trailing semicolon after the last item
-    "wc", test_wc
+    "hostname", test_hostname
 }